Let us see now how one can resolve the information paradox. We can understand the unitary evolution of the black holes using AdS/CFT correspondance [1]}. If we are dealing with time independent and time dependent backgrounds then we can obtain the entanglement entropy of CFT using Ryu-Takayanagi (RT) formula [2]} and Hubney-Rangamani-Takayanagi (HRT) formula [3]}. Quantum corrections to RT formula was done in [4]} and resulting entanglement entropy is known as generalized entropy. Quantum extremal surfaces (QES) can be obtained by extremizing the generalised entropy. One can resolve the black hole information paradox using Island proposal [5]}. The proposal was discussed by the coupling black hole in JT gravity including conformal matter (in conformal field theory (CFT)) at the end-of-the-world bane to same CFT bath in two dimensions. Initially, when there is no island surface, one obtains the linear time dependence of entanglement entropy corresponding to Hawking radiation, at late times, interior of the black hole becomes part of the entanglement wedge of Hawking radiation and starts contributing to the entanglement entropy, island contribution is independent of time. We obtain the Page curve by including these contributions together. Island rule was derived using replica trick from gravitational path integral [6]}, [7]}.
